Page 1 of 1
Air conditioning - electrically driven?
Posted: 24 Jun 2009, 20:12
by silverbullet
Hi All
Has anyone altered or installed an aircon compressor to be driven by an electric motor instead of the engine?
Should be possible as I have also aquired an electric PAS pump in anticipation of finding a RHD power rack...
Would the existing a/c clutch supply be man enough for the job of feeding a motor?
How much hp/kw does an a/c comp draw?
So many questions! Someone must know...

Re: Air conditioning - electrically driven?
Posted: 24 Jun 2009, 20:23
by dugcati
oof.....I wouldnt got there - we all know how much drag the pump puts on the engine when switched on add an electric motor into that mix and your looking a 5-10mpg's at best!
It's gotta be physically possible but I would say you ask yourself "at what cost?"
If you have deep pockets for the fuel (even if on LPG), don't mind every ounce of bhp sapped out of the engine pushing an electric motor/aircon system and 2 ton of van then do it

Re: Air conditioning - electrically driven?
Posted: 24 Jun 2009, 20:36
by silverbullet
Surely electric is more efficient if the alternator is spinning anyway and has excess amperage capacity once the batteries are charged? High-efficiency 12v dc motor?
I was hoping to have the option of running the a/c when on hookup...
Should get the kw meter spinning
A lot of #ahem# modern cars use electric pas

Re: Air conditioning - electrically driven?
Posted: 24 Jun 2009, 20:42
by toomanytoys
Er... no... even modern AC systems draw about 3HP.... get a 3hp electric motor thats not going to burn out in short time...... generating enough power to drive that will use far more power than driving the AC pump directly...
Oh... RHD power rack....

IIRC the last one that came up was about 450 quid.... (a new RHD one form a german source is about £1200) and from what I heard those electric power steering pumps (from a saxo etc) draw quite a bit of juice too..
Re: Air conditioning - electrically driven?
Posted: 25 Jun 2009, 12:32
by silverbullet
Thanks for the info. 3 hp is not insignificant! There isn't a hookup in the land that would stand that, I suspect.
Will (just) reinstate scooby a/c comp with adaptor hoses and chill!
Decided on EPAS system in the column instead of electro-hydraulic mongrel.
70amp Hitachi alternator will put out all we need.

Re: Air conditioning - electrically driven?
Posted: 25 Jun 2009, 22:04
by Other-Power
Claw type alternators are around 30% to 40% efficient.
It is possible to drive an electric A/C unit indirect from the engine via an alternator but you use a lot of power doing it.
I would suggest a direct drive unit with an additional clutch connected to an induction motor so that you can run it from a site hock up.
There should be plenty of space for this with a flat four engine.
Regards
Jonathan
Re: Air conditioning - electrically driven?
Posted: 26 Jun 2009, 09:07
by toomanytoys
Other-Power wrote:
I would suggest a direct drive unit with an additional clutch connected to an induction motor so that you can run it from a site hock up.
There should be plenty of space for this with a flat four engine.
Regards
Jonathan
Nice idea... you havent seen in the back of a petrol T25 have you??

Re: Air conditioning - electrically driven?
Posted: 26 Jun 2009, 09:51
by Other-Power
Lol yah I have, theres loads of room

, just needs a bit of cleaver engineering!
Regards
Re: Air conditioning - electrically driven?
Posted: 26 Jun 2009, 10:07
by toomanytoys

yeah... but with a big ol mains motor in there, you wouldnt want to be trying to fix anything else...

Re: Air conditioning - electrically driven?
Posted: 26 Jun 2009, 13:29
by Other-Power
toomanytoys wrote:
yeah... but with a big ol mains motor in there, you wouldnt want to be trying to fix anything else...

You could easily fit in a 1kW motor in the engine bay and make it work and have plenty of space left over.
you would not need to wack in a massive 3hp motor.
Re: Air conditioning - electrically driven?
Posted: 29 Jun 2009, 08:04
by silverbullet
I appear to have opened a can of (tin) worms here!
Like your ideas though...might have to be an "under the bench" project for the winter!
Re: Air conditioning - electrically driven?
Posted: 01 Jul 2009, 20:41
by sarran1955
Silly idea perhaps.....
In France I can buy a stand alone air conditioner with thermostat and timer for from €184: with a high tech plywood panel for the outlet hose,fitting in the wound down passenger window, and the a/c fitted on a stand behind the passenger seat.
This draws maxi 1200 watts, so fine on a 16 or even 10 amp camping hook-up. Set the timer before you go out, and...hey presto cooooooool van for when you get back. When you're driving open the windows and smell the fresh air.
Cordialement,